1. Technical Field
This invention relates generally to techniques for cleaning and lubricating the sprocket chain of a chain drive mechanism, and more particularly to a technique that uses compressed air both to clean the chain and then to apply a thin coating of lubricant.
2. Background Art
The present invention is useful for cleaning and lubricating, in situ, the sprocket chain of a chain drive mechanism of the type found, for example, in motorcycles and bicycles. For convenience, the invention will be described in the context of a bicycle chain drive.
In a bicycle, the chain drive is constituted by a continuous sprocket chain loop whose links at one end of the loop engage a sprocket associated with the pedals of the bicycle and at the other end engage a sprocket associated with the rear wheel. The arrangement is such that when the pedals are operated to rotate the associated sprocket in the clockwise direction, this acts to advance the sprocket chain loop in the same direction and to drive the rear wheel; but when the pedals are operated to rotate the sprocket counterclockwise, the loop is advanced in the reverse direction and the rear wheel is then disengaged from its associated sprocket. Hence when an assembly in accordance with the invention is used to treat the sprocket chain on a bicycle, one then advances the sprocket chain loop in the reverse direction so that the rear wheel is not driven thereby.
The effort a rider must exert to operate a bicycle depends in good part on effective lubrication. If the wheel bearings and the chain drive are inadequately lubricated, the resultant friction not only makes it more difficult for the rider to pedal the bicycle, but it also results in wear and possible overheating of the sliding metal components, giving rise to destructive metal fatigue. And since the sprocket chain which is exposed has a greasy surface, in the course of operation it tends to pick up grit and dirt particles which adhere to the chain and introduce friction.
Conscientious bicycle owners are aware of the need to maintain the sprocket chain in a clean and well lubricated condition; but with existing expedients for this purpose it is difficult to do so. Thus, before applying a lubricant to the chain, the usual practice is to wipe it clean with a rag to remove the grime therefrom. But since the chain loop is composed of a continuous series of links that are pivotally interconnected, it is difficult with a rag to thoroughly clean the chain. It is even more difficult with a conventional oil can having a nozzle to apply lubricant to the entire chain so that all of its links and their pivot pins are properly lubricated.
The prior art recognizes this problem and discloses various expedients with a view to solving the problem. Thalmann (U.S. Pat. No. 4,593,923) discloses a reservoir which is so attached to the bicycle that as the sprocket chain advances, it passes through the reservoir which contains a solvent as well as brushes to clean the chain. Chiarelli (U.S. Pat. No. 4,578,120) provides a sprocket chain cleaner in which the reservoir is provided with rotary brushes which are turned by the sprocket chain, the reservoir containing either a solvent or a lubricant. The practical drawback to the Thalmann and Chiarelli schemes is that they both use brushes to clean the chain and they both allow the chain being cleaned to emerge wet, thereby allowing dirty solvent to drip on surfaces near the bicycle.
Manning (U.S. Pat. No. 4,783,186) describes a sprocket chain cleaner that uses twin brushes formed by strong flexible bristles, such as nylon bristles, capable of forcefully scrubbing the advancing sprocket chain.
Masonek (U.S. Pat. No. 5,213,180) is a lubricant applicator for a drive chain having a housing with interior flexible plastic bristles.
Pesl (U.S. Pat. No. 6,257,369) describes an apparatus for cleaning and lubricating drive chains, in particular motorcycle drive chains, that includes brushes which are attached in the housing to wipe off the drive chain.
Barbieri (U.S. Pat. No. 6,942,409) describes a bicycle chain cleaner fitted on a spray can of cleaning and lubricating solution that also includes brushes with tufts of radial bristles adapted to penetrate between links of the chain.
There is a long-felt need for an effective chain cleaning and lubrication device that does not rely on brushes and also dries the chain thoroughly.